ipv6 enable (IS-IS)

Function

The ipv6 enable command enables IPv6 capability for the IS-IS process.

The undo ipv6 enable command disables the IPv6 capability.

By default, IPv6 capability is disabled for the IS-IS process.

Format

ipv6 enable [ topology { compatible [ enable-mt-spf ] | ipv6 | standard } ]

undo ipv6 enable

Parameters

Parameter	Description	Value
topology	Indicates the topology type of the IS-IS network. By default, the topology type of the IS-IS network is an IPv4/IPv6 topology. Specifically, IPv4 and IPv6 share the same topology, and only IPv4 routes are calculated.	-
compatible	Indicates that the topology type of the IS-IS network is compatible. Specifically, the IPv4/IPv6 topology and IPv6 topology are compatible.	-
enable-mt-spf	Enables the device to calculate routes for the IPv6 topology when the topology type is compatible. If compatible is specified in the command but enable-mt-spf is not, the device advertises routes to both the IPv4/IPv6 topology and the IPv6 topology but calculates routes only for the IPv4/IPv6 topology.	-
ipv6	Indicates that the topology type of the IS-IS network is an IPv6 topology. If ipv6 is specified in the command, IPv4 links are differentiated from IPv6 links on the IS-IS network, and SPTs are calculated separately for the IPv4 and IPv6 topologies. Specifying ipv6 in the command is recommended.	-
standard	Indicates that the topology type of the IS-IS network is an IPv4/IPv6 topology.	-

Views

IS-IS view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

In IS-IS, IPv4 and IPv6 share an IPv4/IPv6 topology. If both IPv4 and IPv6 address families are deployed in the IPv4/IPv6 topology and only one of the address families is Up, traffic of the other address family is interrupted. In addition, IPv6 routes are not calculated separately in the IPv4/IPv6 topology. As a result, IPv6 traffic cannot be forwarded correctly.

In this situation, run the ipv6 enable command so that IPv6 traffic can be forwarded correctly. For details about the functions with different parameters, see the following table:

Command	Types of Routes to Be Advertised and Saved	Calculates Routes for the IPv6 Topology	IPv6 Traffic Can Be Forwarded Correctly	Usage Scenario
ipv6 enable topology compatible	IPv4 and IPv6	Calculates routes for the IPv6 topology based on the IPv4 topology.	No	IPv4-to-IPv6 transition
ipv6 enable topology compatible enable-mt-spf	IPv4 and IPv6	Calculates routes for the IPv6 topology based on the IPv6 topology and IPv4 routes.	No	IPv4-to-IPv6 transition
ipv6 enable topology ipv6	IPv4 and IPv6	Calculates routes for the IPv6 topology separately based on the IPv6 topology.	Yes	IPv6 network
ipv6 enable topology standard	IPv4	No	No	IPv4 network

Prerequisites

The following operations have been performed:

Enable IPv6 globally using the ipv6 command in the system view.
Enable an IS-IS process using the isis command.

Example

# Enable the IPv6 capability for the IPv6 topology in IS-IS process 1.

<sysname> system-view
[sysname] ipv6
[sysname] isis 1
[sysname-isis-1] ipv6 enable topology ipv6